Boot fitting aid for alpine ski boots

ABSTRACT

The present invention relates to a resilient, conforming device that is worn over portions of the instep, ankle and lower leg to provide an improved fit in alpine ski boots. The device is adapted to be placed between the foot and the ski boot and comprises a resilient, conforming material such that void spaces between the boot and the foot, ankle and lower leg are filled and protuberances of the foot, ankle and lower leg are protected.

FIELD OF THE INVENTION

This invention relates to a device for providing improved fit of a skier's foot in alpine ski boots.

BACKGROUND OF THE INVENTION

Optimum performance in alpine skiing occurs when there is a direct and immediate transfer of movement from the skier's foot and lower leg to the ski. It is therefore desirable to have the ski boot fit snugly around the skier's foot, ankle and lower leg. The bottom of the skier's foot should be in intimate contact with the footbed of the ski boot and there should be intimate and relatively firm contact between the skier's instep, ankle and lower leg and the ski boot. An ideal fit in a ski boot is one that provides both comfort and performance. An ideal fit, however, is sometimes difficult to achieve. Even with the best choice of boot, one that most closely accommodates the specific shape of a particular skier's foot, ankle and leg, there can be localized areas where there are voids between the boot and the skier's foot, ankle and leg or where the contact pressure is too low, causing poor performance, and/or localized areas where the contact pressure is too high, causing discomfort.

A common method used to improve the fit in a ski boot is to place pads on the outside of the removable liner of the boot, with the intent that the liner will be reshaped to conform better to the skier's foot, ankle and lower leg. This method of boot fitting frequently only marginally improves the fit. This is partly because the liner material is relatively rigid and the added padding does not significantly change the shape of the liner so that it might conform to skier's foot, ankle and leg.

Another common method used to improve the fit in a ski boot is to use either off-the-shelf or custom-made footbeds or orthotics to replace the footbed that is supplied with the ski boot. Footbeds and orthotics can provide a more intimate contact between the bottom of the skier's foot and the boot, but they frequently do little to improve the fit around the skier's instep, ankle and lower leg.

Another method used to provide a better fit in ski boots is to stabilize the area of the ankles by using foam, liquid, gaseous, or viscous materials within the liner of boot. Some of these materials have been injected as a liquid state into the liner and then they harden or cure (e.g., polymerize) into a solid. This technology has been applied with mixed results. Some of the materials used in this method of boot fitting are marginally suitable for these applications. Some of these materials do not offer the properties that give the best combination of comfort and performance. The materials can be either too rigid, which makes the fit uncomfortable, or too soft, which reduces performance. In the case of injected foam materials that require curing, the properties of the foam can be difficult to control. The methods used to employ these materials are frequently relatively complex, time consuming, expensive, or otherwise not amenable to mass production or by use of the general public as an after-market method of improving the fit of a previously purchased boot.

Another method used to provide a better fit in ski boots is to use “plug” boots. This method starts with a boot shell that is undersized for the skier and whose walls are thicker than those commonly sold to the public. The boot shell is then reshaped to the skier's foot, ankle and lower leg by grinding, cutting, heating and stretching the shell in selected areas and further modifying the shell by other means known in the boot fitting industry. This method of boot fitting is relatively expensive and time consuming and available in only a few boot fitting shops that provide this service to only a relatively small number of skiers.

It is therefore desirable to provide a convenient, effective and inexpensive method to improve the fit of a skier's foot, ankle and lower leg in alpine ski boots that solves the limitations and problems of footbeds, orthotics, liner pads, injected materials and “plug” boots can do.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a device that improves comfort and performance for alpine skiers by providing a more optimum fit in ski boots. This is accomplished by placing the shaped, resilient, conforming, polymeric foam device between the skier's foot, ankle and lower leg and the inside liner of the ski boot, to provide intimate contact and optimum contact pressure between the skier's foot, ankle and lower leg and the ski boot. The device solves many of the problems described in the BACKGROUND OF THE INVENTION. The device can be pre-made to an optimal shape from a material with optimal properties, which allows it to be more convenient, less time consuming, less expensive, more controllable and more effective than other materials and methods currently available. The device is placed between the skier's foot and ski boot liner, allowing it to be placed exactly where it is needed to fill in the void spaces between the boot and the skier's foot, ankle and lower leg, thus providing the best combination of comfort and performance.

One object of this invention is to provide a resilient, conforming device that will give intimate contact and uniformly distributed contact pressure between the skier's instep, ankle and lower leg and an alpine ski boot to provide greater skier comfort and better skiing performance. Another object of this invention is to provide a resilient, conforming device that will fill voids between a skier's instep, ankle and lower leg and an alpine ski boot to eliminate localized areas of low contact pressure between those areas and the ski boot. Another object of this invention is to provide a resilient, conforming device that will surround protuberances on the skier's instep, ankle and lower leg to eliminate localized areas of high contact pressure between those areas and an alpine ski boot. Another object of this invention is to provide a resilient, conforming device that is made from material that is sufficiently soft and conformable to provide a comfortable fit and yet is sufficiently rigid or viscoelastic to provide efficient transfer of movement from the skier's foot, ankle and lower leg to the ski boot and ski. The device of this invention satisfies all of the objects listed above.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 shows a device of this invention that was made from a sheet of foamed polyurethane.

FIG. 2 shows a device of this invention that is placed on a foot, viewed from the front and covers portions of the instep, ankle, and lower leg.

FIG. 3 shows a device of this invention that is placed on a foot, viewed from the side and covers portions of the instep, ankle, and lower leg.

DETAILED DESCRIPTION OF THE INVENTION

The device of this invention can be constructed of a resilient, polymeric foam material. Examples of a resilient, polymeric foam material include foamed polyethylene, foamed ethyl vinylacetate (EVA), and foamed polyurethane, both highly resilient and slow recovery polyurethane. The polymeric foam material can be either single or multi durometer such as found in laminated materials. The device can be cut from a polymeric foam sheet of appropriate thickness, commonly available from suppliers of orthotic materials. The device can be further shaped by grinding, sanding and heat forming methods known in the foot orthotic industry. Alternatively, the device can be made by injection molding.

The material for the device of this invention is chosen to give the desired functionality. Material properties to be considered include resiliency, compressibility, hardness, recovery force and rate, grindability, adherence to human skin, moisture absorbance, allergic reactions, and degradation by environmental and human contact.

The optimum size, shape and thickness of the device of this invention depends on the size and shape of the skier's foot, how well his foot, ankle and lower leg fit into the ski boot and on what is needed to achieve a good fit. The device generally covers portions of the skier's instep, ankle and lower leg. A typical shape of the device is shown in FIG. 1. Areas of the instep, ankle and lower leg typically covered by the device are shown in FIGS. 2 and 3. The size, shape and thickness of the device can be individually tailored to the skier and boot combination to provide an intimate, firm and comfortable fit, especially in the regions of the upper instep, anterior portion of the ankle and the medial surface of the lower leg.

Some of the boot fitting problems the device of this invention addresses include a low instep, a protruding ankle bone, an excessively concave medial surface of the tibia, irritation of the instep, ankle, and shin by the boot tongue, and small ankles.

The device of this invention can be held in place on the skier's foot and lower leg by several means. In one instance the pads can be placed under a sock, directly against the skin. In this case the device should be of a composition such that the surface of the device that contacts the skin is relatively smooth and soft, so that the device does not slide easily on the skin. In another instance the device can be held in place by placing it under an elastic band, which is fitted over the foot and/or lower leg. In this instance the device might be attached to the elastic band. In another instance the device can be attached to the inside or outside of a sock or woven into a sock so that the device is in the proper position when the sock is placed on the skier's foot.

A ski boot technician skilled in boot fitting can easily and readily construct the device of this invention and fit it to a skier. The technician might examine the skier's foot to determine the approximate size, shape, and thickness of the device needed to achieve a good fit. A device of approximately the proper size, shape and thickness might then either be prepared or chosen from an assortment of previously constructed devices. The device might then be placed on the skier's foot, typically under a sock. The skier might then insert his foot into the boot and describe where there are areas of high and/or low pressure. This information might then be used to construct or modify a device as needed to provide an optimum fit. 

1. A device comprising a resilient, conforming material that covers a portion of the instep, the anterior portion of the ankle and the medial surface of the lower leg such that it provides conforming contact between those areas and an alpine ski boot.
 2. A device comprising a resilient, conforming material that covers the anterior portion of the ankle and the medial surface of the lower leg such that it provides conforming contact and conformance between those areas and an alpine ski boot.
 3. A device comprising a resilient, conforming material that covers a portion of the medial area of the lower leg such that it provides conforming contact and conformance between that area and an alpine ski boot.
 4. A device according to claims 1, 2, 3, or 4 wherein the comprised material is from 0.0625 to 0.75 inch thick.
 5. A device according to claims 1, 2, 3, or 4 wherein the edge of the device has been tapered or rounded.
 6. A device according to claims 1, 2, 3, or 4 wherein the comprised material is from 5 to 50 Shore A durometer hardness.
 7. A device according to claims 1, 2, 3, or 4 wherein the comprised material is foamed, slow recovery polyurethane.
 8. A device according to claims 1, 2, 3, or 4 wherein the comprised material is foamed polyethylene.
 9. A device according to claims 1, 2, 3, or 4 wherein the comprised material is foamed poly(ethyl vinylacetate) (EVA). 